Power Operations Bulletin # 805
ERCOT has posted/revised the Transmission and Security manual.
The Various Changes are shown below.
A copy of the procedure can be found at:
http://www.ercot.com/mktrules/guides/procedures/index.html
4.5 GTC Stability Limits
Procedure Purpose: Maintain transmission stability within the ERCOT region when there is a Generic Transmission Constraint (GTC).
Protocol Reference / 6.5.9.1(1)(e)Guide Reference / 2.2.2 / 4.5.2(2)(b)
NERC Standard / IRO-001-4
R1 / IRO-002-4
R3 / IRO-006-TRE-1
R1, R2 / IRO-008-2
R2, R3
TOP-001-3
R1, R14 / TOP-002-4
R2, R3
Version: 1 / Revision: 176 / Effective Date: AugustJune 31, 2017
Step / Action /
Panhandle Stability
Weighted Short Circuit Ratio / The value of the limit on transfers across the Panhandle GTC will be set by the lower good value of the voltage stability limit (VSAT) or the system strength limit (WSCR).1 / WHEN:
· VSAT runs and provides an updated limit for the Panhandle Stability;
THEN:
· Update RTMONI.
WHEN:
· The BASECASE PNHNDL is approaching 85% of the limit;
THEN:
· Activate the BASECASE PNHNDL constraint in TCM, AND;
· Raise the BASECASE PNHNDL to 95% as the flow stabilizes.
NOTE / For an unsolved contingency scenario, activate the BASECASE PNHNDL constraint to get the contingency to solve. This may require setting the %Rating lower than 85%.
Topology
Change / IF:
· A topology change occurs;
THEN:
· Re-run RTCA and VSAT.
IF:
· A constraint needs to be controlled before the next SCED run
THEN:
· Manually run RTCA after activating the constraint, AND
Manually execute the SCED process
Log / Log all actions.
Laredo Area Stability
1 / WHEN:· All lines are in-service there is a local voltage stability issue in the Laredo area;
WHEN:
· VSAT runs and provides an updated limit for the Laredo Area Stability;
THEN:
· Update RTMONI.
WHEN:
· The BASECASE LAREDO flow is approaching 90% of the limit in TCM;
THEN:
· Activate the constraint
· The constraint activates AND;
· Raise the BASECASE LAREDO to 95% as the flow stabilizes.
Topology
Change / IF:
· A topology change occurs;
THEN:
· Re-run RTCA and VSAT.
IF:
· A constraint needs to be controlled before the next SCED run
THEN:
· Manually run RTCA after activating the constraint, AND
· Manually execute the SCED process
2 / Instruct Resource Operator to deploy Non-Spin in the Laredo area
NOTE / When the Non-Spin Resource is on-line, they must change their Non-Spin schedule to 0 in order for SCED to dispatch them.
3 / VDI QSGR in the Laredo area that were not bid in as Non-Spin.
Request:
1.0 RUC Operator to issue electronic Dispatch Instruction to commit
4 / IF:
· One of the following conditions exist without a generation solution:
o Unsolved contingency
o Post-contingency overload above 125%
o Laredo area is above 100%
THEN:
· Issue a Transmission Emergency Notice
o Make Hotline call to TOs
o Posting message on MIS Public
o Notify Real-Time Desk to make Hotline call to QSEs
T#29 - Typical Hotline Script for Transmission Emergency for the Rio Grande Valley or Laredo Area
Typical MIS Posting Script:
Transmission Emergency Notice has been issued for the Laredo area due to [state issue used in hotline call].
Edit script as needed to fit situation.
5 / IF:
· The Transmission Emergency is issued, AND
· One of the following conditions exist without a generation solution:
o Unsolved contingency
o Post-contingency overload above 125%
o Laredo area is above 100%
THEN:
· Request DC-Tie Operator to curtail any exports on the Laredo DC-Tie
· Request emergency energy from the appropriate DC-Tie Operator across the Laredo DC-Tie.
NOTE / DC Tie exports shall not be curtailed during the Adjustment Period, or for more than one hour at a time, except for the purpose of maintaining reliability.
LOG / Log all actions.
Zorrillo – Ajo 345kV Stability
Note / All lines are in-service, Rio Hondo 345 kV Series Cap in-service and improved reactive controls (capacitor switching scheme at Texas Gulf Wind is available) there is no local voltage stability issue in South Texas near Ajo.1 / IF:
· An outage has occurred on any of the identified elements in the table;
THEN:
· Refer to the constraint limit,
WHEN:
· The BASECASE ZO_AJO is approaching 85% of the limit;
THEN:
· Activate the BASECASE ZO_AJO constraint in TCM
· The constraint activates AND;
· Raise the BASECASE ZO_AJO to 98% as the flow stabilizes.
2 / If there is more than one line out of service or AEP is unable to manage the reactors at Ajo to control voltages, use the most restrictive limit in RTMONI. With more than one line out of service, this becomes more of a thermal issue and RTCA will most likely be more binding than the GTC.
Log / Log all actions.
Red Tap Stability
NOTE / When all lines are in-service, there is no local voltage stability issue.1 / IF:
· An outage has occurred on the identified element in the table (identified in Desktop Guide Transmission Desk 2.12);
THEN:
· Refer to the constraint limit from table to set the value (identified in Desktop Guide Transmission Desk 2.12);
· Update RTMONI from table;
WHEN:
· The BASECASE REDTAP flow is approaching 85% of the limit in TCM;
THEN:
· Activate the BASECASE REDTAP constraint in TCM
· The constraint activates AND;
· Raise the BASECASE REDTAP to 98% as the flow stabilizes.
Log / Log all actions.
PomeloNorth Edinburg – Lobo Stability
NOTE / When all lines are in-service, there is no local voltage stability issue.1 / IF:
· An outage has occurred on the identified element in the table (identified in Desktop Guide Transmission Desk 2.12);
THEN:
· Refer to the constraint limit from table to set the value (identified in Desktop Guide Transmission Desk 2.12);
· Update RTMONI from table;
WHEN:
· The BASECASE PomeloNE_LOB flow is approaching 85% of the limit in TCM
THEN:
· Activate the BASECASE POMELO NE_LOB constraint in TCM
· The constraint activates AND;
· Raise the BASECASE POMELO NE_LOB to 98% as the flow stabilizes.
Log / Log all actions.
5.1 Outages
Procedure Purpose: Monitor and respond to various types of equipment outages, both Transmission and Generation, in order to maintain reliability of the ERCOT Grid.
Protocol Reference / 3.1.1(2)(j) / 3.1.4.2 / 3.1.4.4 / 3.1.4.53.1.4.6 / 3.1.5.1 / 3.1.5.4 / 3.1.5.5
3.1.5.7 / 3.1.5.11 / 3.1.6.11(2) / 6.5.7.1.6
6.5.7.1.10(2)(c) / 6.5.7.1.6
Guide Reference / 2.4
NERC Standard
Version: 1 / Revision: 132 / Effective Date: AugustFebruary 31, 20176
Step / Action /
NOTE / ERCOT Operators can only make the following changes in the Outage Scheduler:
· Remove actual start/end time if it is within 2 hours of the time the MP entered the outage,
· Change status,
· Add notes
If a MP needs assistance or is unable to enter their outages, direct them to Outage Coordination. Outage Coordination has an “Impersonation” certification that will allow them to make the needed changes.
NOTE / Forced Outages should be verbally communicated to ERCOT and must be entered into the Outage Scheduler if it is to remain an Outage for longer than two hours.
1 / IF:
· An Emergency Condition is declared;
THEN:
· Determine if Outages can be returned to service if causing negative impacts to reliability,
· Coordinate with the appropriate TO.
Monitor Mode
1 / IF:· Any outages, either planned or forced, that may require additional monitoring;
THEN:
· Mark the outages in the Outage Scheduler OS Monitored Outage display as deemed necessary,
· Verify that the marked outages are in monitor mode,
· Continue to monitor the marked outages.
Forced and Unavoidable Extensions
1 / IF:· A Forced or Unavoidable Extension is received, review the outage details;
THEN:
· Monitor congestion and make appropriate changes as necessary,
· Determine if it will have an effect on previously approved outages which may need be to withdrawn.
Remedial Switching Action
Definition / “Remedial Switching Action” is a Forced Outage sub-type in the Outage Scheduler. ERCOT must approve all Remedial Switching Actions prior to implementation by TOs.< 3 Days in length / Remedial Switching Actions are limited to a maximum of 3 days.
> 3 Days in length / If the Remedial Switching Action is required to remain active for longer than 3 days, a Planned Outage must be submitted to change the position of effected breakers and switches.
Approve / IF:
· No issues identified;
THEN:
· Approve the Outage as received.
Reject / IF:
· Reliability issues;
THEN:
· Notify Operations Support Engineer;
· Reject the outage to ensure system reliability.
Restoration / Breakers and switches in a Remedial Switching Action must be able to be returned to their normal position within 4 hours or less (this allows for drive time for remote switches w/o SCADA).
Log / Log all actions.
Maintenance Outages
Definition / · Level 1- Equipment that must be removed from service within 24 hours to prevent a potential Forced Outage;· Level 2 - Equipment that must be removed from service within 7 days to prevent a potential Forced Outage; and
· Level 3 - Equipment that must be removed from service within 30 days to prevent a potential Forced Outage.
Maintenance Outage with start time ≤ 24 Hours / IF:
· A Maintenance Outage is received, review the outage if the scheduled start time is within the next 24 hours;
THEN:
· Run a study to determine if the outage will cause any reliability issues.
Approve
Maintenance Outage with start time ≤ 24 Hours / IF:
· No reliability issues identified;
THEN:
· Approve the Maintenance Outage.
Coordinate Maintenance Outage with start time ≤ 24 Hours / IF:
· Reliability issues exist;
THEN:
· Coordinate the start of the outage with the TO to ensure system reliability as long as the outage is allowed to start within 24 hours, AND
· Approve the Maintenance Outage.
Coordinate
Maintenance Level 2 and 3 Outage ≤ 24 Hours / IF:
· Maintenance Level 2 and 3 outages are received with a start time of less than the next 24 hours, AND
· Reliability issues exist;
THEN:
· Coordinate the start of the outage with the TO to ensure system reliability as long as the outage is within the allowed Maintenance Level 2 (7 Days) and 3 (30 Days) outage criteria,
· ERCOT Outage Coordination group may help coordinate a new start time,
IF:
· Reliability issues continue,
THEN:
· REQUEST the Operations Support Engineer investigate the development of a MP or TOAP (see section 4.7 Mitigation Plan),
· Approve the Maintenance Outage after coordination.
Maintenance Level 2 and 3 Outages / IF:
· Maintenance Level 2 and 3 outages are received with a start time of greater than the next 24 hours;
THEN:
· The ERCOT Outage Coordination group has a process to review all Maintenance Level 2 and 3 outages without further action.
Log / Log all actions.
Consequential Outages
1 / WHEN:· A TO enters the breaker and switch statuses associated with an Electrical Bus;
THEN:
· A downstream topology processor will evaluate the breakers and switches associated with the applicable Electrical Bus to determine if the Electrical Bus is consequentially outaged, and to thereby designate the status of the Electrical Bus.
Evaluate / IF:
· The TO has submitted the outage in the Outage Scheduler;
THEN:
· As time permits, perform a study to determine the effects the outage has on the ERCOT system and evaluate the request and verify the Outage meets the applicable requirements.
No
Violations / IF:
· NO, violations of applicable reliability standards exist;
THEN:
· Approve the request in the Outage Scheduler.
Yes
Violations / IF:
· YES, violations of applicable reliability standards exist;
THEN:
· Reject the request in the Outage Scheduler.
Log / Log all actions.
Returning from Planned Outage Early
1 / Before an early return from an Outage, a Resource Entity or QSE may inquire of ERCOT whether the Resource is expected to be decommitted by ERCOT upon its early return.IF:
· A QSE is notified by ERCOT that the Resource will be decommitted if it returns early and the Resource Entity or QSE starts the Resource within the previously accepted or approved Outage period,;
THEN:
· The QSE representing the Resource will not be paid any decommitment compensation.
Guidelines for Withdrawal of an Outage
1 / IF:· Security analysis and/or Operator experience indicates that an “Approved” or “Active” outage may have an adverse impact on system reliability;
THEN:
· Review the restoration time of the outage and if necessary,
· ERCOT may withdraw the outage.
2 / WHEN:
· ERCOT withdraws an outage via the Outage Scheduler;
THEN:
· Enter an explanation in the “Reviewers Notes” listing the reliability concerns that caused the withdrawal,
· Notify the following, by e-mail, as soon as possible:
o OPS Outage Coordination
o OPS Support Engineering
o 1 ERCOT Shift Supervisors
· Include the following information:
o From Station – To Station (if applicable)
o The planned Start and End date of the outage.
3 / IF:
· A TO or QSE reports that the outage in question has progressed to a point that withdrawal is not practicable within the outages designated restoration time;
THEN:
· Record this information in the “Outage Scheduler Reviewer’s Notes”,
· Log the outage in the Transmission Security Log,
· Inform the Shift Supervisor,
· Continue monitoring system security,
· Request Operations Support Engineer to develop Mitigation plan if necessary.
Approval of an Outage on Transmission Devices of More than one hour duration
1 / IF:· A verbal request for permission to remove a transmission device from service for more than one hour is received;
THEN:
· Verify with the TO that the work being done will not prevent the device from being placed back in service immediately if needed,